Whether in the prehistoric caves of Europe or the Drakensberg Mountains of South Africa, artists saw visions and recreated them on rock walls. But the act of making these images seemed to be the exclusive preserve of a select few. So how did we get from there, to today's modern world where just about everyone can make a picture?

The rock art was part of a site reserved for an initiation ceremony for girls.

David Whitely, an expert on California rock art sites, became fascinated with ancient rock images painted in the heart of the Cahuilla Indian community in Riverside County. Images not hidden away, but seemingly painted for everyone to see.

The rock art was part of a site reserved for an initiation ceremony for girls. The ceremony began with the girls being placed in pits and given hallucinogenic tobacco.

"The idea being that…would ultimately cause them to have visionary images, one of which would be their spirit helper, they would obtain supernatural power that would help them not only through childbirth but throughout their lives. "

"At the termination of their puberty initiation, they would run up to these sites, these sites located centrally in their villages…and then they would paint the spirit helper that they saw during their visionary experience on the wall."

At other sites, boys went through a similar ritual at the onset of their puberty. It meant everyone had this experience. In other words, pictures had gone from being the exclusive property of a shaman/artist, to being owned by the entire tribe.